The present application relates to optical device packages, and in particular to a package for enclosing a wavelength division multiplexing (WDM) coupler.
Optical devices, such as WDM couplers, require special packaging for protecting the devices from mechanical, as well as thermal, stresses. Much of the difficulty in designing a suitable package arises from the fact that the optical devices are comprised of several elements with different diameters that have been fixed, e.g. glued, together. Moreover, no two devices are identical, because during assembly the elements are individually adjusted to obtain the highest possible optical coupling.
Conventional packages for optical devices include a rigid outer housing surrounding a rigid insert, into which the optical device is mounted and fixed. To avoid thermally induced stress, the insert is made up of a material that has thermal-expansion characteristics that are similar to those of the optical device. After the optical device is fixed to the insert, the rigid outer housing is glued or otherwise sealed together over the insert. Alternatively, if the outer housing is a rigid cylindrical sleeve, it is slipped over the optical device with the insert, and then sealed at each end. If strain relief is required, it is usually provided by mounting resilient tubes over the fibers prior to assembly, and fixing them in position during assembly. All of the aforementioned packages require several labor intensive assembly steps, while providing only limited protection. Moreover, if strain relief is required, the tubes must by positioned on the fiber before the optical device is assembled, adding to the complexity of the assembly process.
An object of the present invention is to provide an optical device package that overcomes the shortcomings of the prior art, and provides increased protection to the enclosed optical device. Another object of the present invention is to provide an optical device package that can be assembled quickly and easily without the need for labor intensive steps. Another object of the present invention is to provide a package with integrated strain relief.
Accordingly, the present invention relates to a package for an optical device of the type comprising a plurality of elements including a first element that is not coaxial with a second element, the package comprising:
base means having a first resilient inner section, and a first protective outer section, said first resilient inner section having a first raised portion for engaging the first element of the optical device;
cover means having a second resilient inner section, and a second protective outer section, said second resilient inner section having a second raised portion for engaging the first element; and
clamping means for securing the base means to the cover means, whereby the first element is held between the first and second raised portions.
Another aspect of the present invention relates to a package for a device of the type comprising wires or fibers extending therefrom, the package comprising:
base means having a first resilient section at one end thereof including a first strain relief means;
cover means having a second resilient inner section at one end thereof including a second strain relief means; and
clamping means for securing the base means to the cover means, whereby the first and second strain relief means form an annular strain relief member with a bore that gradually increases in diameter from an inner end proximate the device to an outer end remote from the device;
wherein the first strain relief means includes first mating surfaces, each extending from an inner edge at the bore to an outer edge at an outer surface thereof; wherein the second strain relief means includes second mating surfaces, complementary with the first mating surfaces, extending from an inner edge at the bore to an outer edge at an outer surface thereof; and wherein the inner edges of the first and second mating surfaces define a line, at least a portion of which is arcuate.